Imprinting machine and method of operation

ABSTRACT

An imprinting machine, and method of operation thereof, in which work members, such as cartons or labels, or the like, which are to be printed are fed through the machine with the machine having a rotary printing head, preferably heated, and a transfer, or printing, ribbon disposed between the printing head and the workpiece. The printing head rotates continuously and is moved to and from imprinting position by a fluid cylinder. The advancing of the ribbon is synchronized with rotation of the head and takes place only when the printing head moves to printing position, thus conserving the ribbon and causing ribbon advance only when necessary. The ribbon is advanced by means of a stretch belt connected to the print head and the ribbon wind-up spool which is drawn tight to advance the ribbon when the head is moved to the imprinting position.

1451 Apr. 22, 1975 United States Patent 1191 Coffelt [5 IMPRINTINGMACHINE AND METHOD OF 3.537.393 11/1970 101/235 OPERATION FOREIGNPATENTS OR APPLICATIONS Germany 101/244 3 6 9 H 2 6 oo 6 3 t S S k k um93 m4 fi.m O h S. m pk 6 DH R 0 t. n e V n l. 6

Primary E.\'aminerRobert E. Pulfrey Assistant E.\'amt'ner--WilliamPieprz Agent, or FirmAlbert L. .leffers; Roger M.

v. w H 0 t t A 3 7 9 l 3 8 H r n. m A3 0 N .L P F n. FA NH 22 RickertABSTRACT An imprinting machine, and method of operation thereo f, inwhich work members, such as cartons or labels, or the like, which are tobe printed are fed L ,1 7 57 433 munm w l. l 4 M B63. 2 M 0 M 7 1 .3 .aW32 5 t 3 4 2 "n U m/ w M m 7 n W J m mfis mSw .l f C lo WM Mk U [F .H Hm 5 55 through the machine with the machine having a rotary printinghead, preferably heated, and a transfer, or printing, ribbon disposedbetween the printing head [56] References Cited UNITED STATES and theworkpiece. The printing head rotates continu- PATENTS ously and is movedto and from imprinting position by a fluid cylinder. The advancing ofthe ribbon is synchronized with rotation of the head and takes placeonly when the printing head moves to printing position, thus conservingthe ribbon and causing ribbon advance only when necessary. The ribbon isadvanced by means of a stretch belt connected to the print head and theribbon wind-up spool which is drawn tight to advance the ribbon when thehead is moved to the imprinting position.

5 Claims, 7 Drawing Figures m.mm m .m unuug "n" L "uv "rh u a m y mm h ta s mw mc n mmn ommmm mulmmoo SBKBSMTRCFCG 92379 2344009 455556666666999999999999 HHHHHHHHHHH 52 73 2220 IMPRINTING MACHINE AND METHOD OFOPERATION The present invention relates to an imprinting machine and toa method of operation thereof and is particularly concerned with a highspeed hot imprinting machine.

Imprinting machines for imprinting labels, boxes, cartons and the like,are known but, heretofore. have presented certain problems. Many of themachines are of the start and stop type with the printing head movingintermittently and some are the type in which the printing headreciprocates to and from printing position. while in others the feed ofthe ribbon which carries the imprinting material is not synchronizedwith the printing operation.

With the foregoing in mind, a primary objective of the present inventionis the provision of an imprinting machine, and a method of operationthereof, in which the drawbacks referred to above are eliminated.

Another object of the present invention is the provision of animprinting machine of simplified construction which will operateextremely rapidly.

Still a further object is the provision of an imprinting machine thatcarries out an imprinting operation only when a workpiece, such as acarton, label, or the like is advanced into the machine.

Still another object of the present invention is the provision of animprinting machine having a rotary printing head and wherein the ribbonfeed takes place only while the printing head is rotating and imprintingsimultaneously.

BRIEF SUMMARY OF THE INVENTION According to the present invention. adrive shaft is mounted in the frame of the machine and is continuouslydriven in rotation. Extending in the same plane as the drive shaft, andpositioned above the drive shaft, is a printing shaft supported in abracket which is pivotally attached at one end to the frame of themachine so that the printing shaft can be tilted relative to the driveshaft in the plane of the shafts. At the one end the printing shaftcarries a gear which meshes with another gear on the drive shaft andthese gears remain in mesh in all tilted positions of the printingshaft. At the end of the printing shaft opposite the aforementionedgears, is a printing head which has the type face, or the like, thereonwhich is to be imprinted. The tilting of the printing shaft isaccomplished by an air cylinder connected to the support frame of theprinting shaft which can be reversibly energized for tilting theprinting shaft up and down in the machine.

The frame of the machine carries a ribbon supply reel and a ribbontake-up reel and the ribbon is guided therebetween and across beneaththe printing head and in spaced relation thereto when the printing headis in retracted position. Directly opposed to the printing head is apressure roller and, when the printing head is advanced downwardly, thehead engages the back of the ribbon and presses the ribbon against aworkpiece passing therethrough, with the workpiece being, in turn,pressed against the pressure roller. The printing head is preferablyheated and this causes material carried by the ribbon on the side facingthe workpiece to be transferred thereto. The printing shaft and printinghead rotate continuously but up and down movement of the printing shaftand printing head is under the control of a detector which detects themovement of a workpiece into working position.

The foregoing objects as well as still other objects and advantages ofthe present invention will become more apparent upon reference to thefollowing detailed specification taken in connection with theaccompanying drawings in which:

FIG. I is a perspective view looking in at a printing machine accordingto the present invention from the front.

FIG. 2 is a perspective view similar to FIG. I, but looking in at themachine from the back.

FIG. 3 is a side view of the machine. looking in from the right side ofFIG. I and the left side of FIG. 2, and partly broken away.

FIG. 4 is a somewhat schematic front view of the machine.

FIG. 5 is a sectional view indicated substantially by line 5-5 on FIG.3.

FIG. 6 is a schematic view showing the printing head and the heaterstherefor and the thermostat mounted on the side of the printing headwhich controls the supplyof energy to the heaters.

FIG. 7 is a schematic representation of a control circuit for theimprinter according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings somewhatmore in detail, and with particular reference to FIGS. 1 to 5, theprinter comprises a frame 10 adapted for supporting the unit when usedby itself and also for supporting the unit when the unit is placed inline to cooperate with other machinery.

A drive shaft 12 is rotatably mounted in frame 10 and is adapted forbeing connected to a source of driving power, such as a motor, or suchas a drive member of a machine with which the imprinter is placed inline. Drive shaft 12 carries a drive gear 14 and this gear meshescontinuously with another gear l6,'which is mounted on a printing shaft18. Printing shaft 18 is supported by a bracket structure 20, which atthe end thereof adjacent gears 14 and 16 is pivotally connected to mainframe 10 as by pivot means 22.

At the end of shaft 18 opposite gear 16 there is a printing head 24'which, as will best be seen in FIG. 1, is somewhat flattened on thesides and on one face carries type or the like, generally indicated at26, and which is the material, or legend, or symbol, or the like, whichis to be imprinted on a work member.

The bracket 20, intermediate the ends thereof, is pivoted as at 28 to ayoke 30 extending upwardly to above bracket 20 and connected to the ram32 of a double acting air motor having a cylinder 34 to the ends ofwhich are connected air conduits 36 and 38.

Also carried by the main frame, as on a spindle 40, as a ribbon supplyreel 42 about which a ribbon 44 is wound. Also carried by main frame 10is another spindle 48 on which a ribbon take-up reel 50 is rotatablymounted.

The ribbon passes downwardly from supply reel 42 and over a first guideroller 52 and then extends horizontally across beneath printing head 24and about a second guide roller 54 and then vertically upwardly totake-up reel 50. Wire ribbon guides 56 and 58 assist in guiding theribbon to and from the guide rollers 52 and 54. The ribbon 44 is inspaced reiation to the printing head 24 when the printing head is in anupper, retracted position but passes closely above a pressure roller 60which is in the same vertical plane as printing head 24.

- As will best be seen in FIG. 3, pressure roller 60 is mounted on abracket 62 that can be vertically adjusted in the machine as by thethreaded adjusting screw 64 and clamped in adjusted position as by clampscrew means 66. By providing for the adjustability of pressure roller 60various thicknesses of workpieces can readily be accommodated for.

FIG. 3 will also show an adjustable stop screw 68 which is provided tolimit downward movement of printing head 24 when motor 34 is energizedto thrust yoke 30 in the downward direction.

The take up spindle 50 is provided with a drive pulley 70 and mounted onshaft 18 behind printing head 24 is a pulley 72. There is entrainedabout these two pulleys a resilient drive belt 74 which may be ofrubber-like material, or which may be in the form of a coil spring. Thelength of belt 74 is so selected that when the printing head 24 isretracted to its upper position as illustrated in FIG. 3, the drive beltdoes not drive ribbon take-up reel 50. However, when the printing headis moved downwardly into printing position by the fluid motor, the belt74 is drawn taut into driving relation with pulleys 72 and 70 and doescause rotation of ribbon take-up reel 50. By this arrangement, theribbon take-up reel is only driven when the printing head is loweredinto printing position so that the use of ribbon is quite economicalwith the ribbon only advancing when it is necessary during a printingoperation.

Since the machine is adapted to operate at relatively high speed, it isof advantage to prevent the supply reel 42 from turning too much whileit is also desirable to retain the ribbon taut between the reels 42 and50. To this end, an adjustable drive brake arrangement 76 is associatedwith reel 42 and supplies sufficient drag thereto to permit feeding ofthe ribbon from reel 42, while preventing reel 42 from running ahead atany time.

In a machine of the nature disclosed herein it is advisable for theprinting material, which is on the side of ribbon 44 which faces awayfrom the printing head, to he heat sensitive and to this end theprinting head 24, as shown in FIG. 6, comprises heater means 78,preferably electrically operable, and connected in circuit with athermostatic element 80 and also carried by the printing head. In thismanner, the temperature of the printing head can be closely controlled.

As will best be seen in FIG. 3, the connection tothe thermostaticelement and heating means, is accomplished by way of the double slipring arrangement 82 mounted on shaft 18 and which is engaged by brushes,one of which is indicated at 84 in FIG. 3. The wires leading from theslip rings to the thermostatic element and heating means can be takenalong the shaft in a groove or inside the shaft and then connected tothe heating means and thermostatic element by wires.

Also carried on drive shaft 12 is a cam 90 which is employed inconnection with controlling the machine as shown in FIG. 7. Cam 90 willbe seen to control a limit switch LS1 which closes on a contact 92 whencam-90 is in one position and on a contact 94 when cam 90iis in anotherposition.

Contact 94 is connected through a first solenoid S1 with power line Ll,while contact 94 is connected through a sccond solenoid S2 with powerline L1. The solenoids pertain to a self-centering air valve 96 which isconnected via the aforementioned conduits 36 and 38 with the oppositeends of air cylinder 34 for causing reciprocation of ram 32 which isconnected to the aforementioned yoke 30.

The blade of limit switch LS1 is connected with a contact 98 pertainingto a limit switch LS2, the blade of which is connected to power line L2and which blade normally rests on a contact 100. When a work member,indicated at 102, approaches working, or printing, position, the bladeof limit switch LS2 will be moved into engagement with contact 98 andthis will supply energy to limit switch LS1 which will move betweencontacts 92 and 94 in conformity with the rotated position of cam andthereby controlling the up and down movement of the printing head duringcontinued rotation thereof.

It will be apparent that as soon as a workpiece moves out of the rangeof switch LS2, the up and down movement of the printing head will beinterrupted. Normally, for a single workpiece there will be a singledownward movement of the printing head, although it is conceivable for along ribbon-like workpiece consisting, perhaps, of interconnectedlabels, that the up and down movement of the printing head would besubstantially continuous. In any case, the cam 90 is so oriented on theprinting shaft 18 relative to the printing head that the up and downmovement of the printing head takes place in the proper timedrelationship to the operation of the remainder of the machine and to themovement of workpieces in the space between printing head 24 andpressure roller 60.

It will be evident that the machine of the present invention is capableof operating at high speed and that it can be adjusted to acceptrelatively thick work members and relatively thin work members; that itcan be operated independantly; or it can be seen in line with anothermachine.

It will be evident that the adjustments impart flexibility to themachine and permit the aforementioned high speed operation thereof in areliable manner.

It might be noted that the precise ribbon position laterally in themachine can be accomplished by adjustment of the wire ribbon guides 56and 58, as by availing of screws 104 by means of which the ribbon guidescan be locked in adjusted positions.

The machine according to the present invention is relatively inexpensiveto construct, and, as mentioned, is quite reliable in operation and willoperate reliably at high speed. The machine is particularly conservingof ribbon because the ribbon only moves while the printing head is inprinting position and does not rotate when the printing head is inretracted position.

Modifications may be made within the scope of the appended claims.

What is claimed is:

1. In an imprinter; a frame, a rotary printing head and a pressuremember in radially opposed relation in said frame, means in said framefor advancing said printing head toward said pressure member intoprinting position and for retracting said printing head away from saidpressure member into idle position, ribbon supply means operable tosupply a ribbon into the space between said printing head and pressuremember which will imprint on a workpiece disposed between the ribbon andsaid pressure member when said printing head is advanced into printingposition, feed means for feeding said ribbon in the circumferentialdirection of said printing head when the printing head is advanced intoprinting position, said ribbon supply means includes means for rotatablysupporting a ribbon supply reel on said frame on one side of saidpressure member, said ribbon feed means being disposed in said frame onthe other side of said pressure member, a ribbon wound up on the supplyreel and leading therefrom to said feed means, first means for drivingsaid print head in rotation continuously, and second means for drivingsaid feed means only while said printing head is advanced into printingposition, and a bracket, a printing shaft journaled in said bracket andhaving said printing head mounted on one end thereof, pivot meanspivotally connecting the end of said bracket opposite the print head tosaid frame and said means for advancing and retracting said printinghead comprising a reversible actuator connected between said frame andan intermediate point of said bracket, said feed means including a takeup reel rotatable in said frame and to which said ribbon is connected, apulley on said printing shaft, a pulley connected to said take up reel,and a stretch belt entrained about said pulleys, movement of saidprinting head into printing position drawing said belt tight to causedriving of said take up reel.

2. An imprinter according to claim 1 in which said ribbon supply meanscomprises a supply reel rotatable in said frame and from which saidribbon leads, and a drag brake connected to said supply reel.

3. An imprinter according to claim 1 in which said reversible actuatorincludes a double acting fluid motor having a reciprocable ram, and ayoke connected to said ram and pivotally connected between said frameing in unison with said printing head and operable to' actuate saidswitch means to cause said printing head to advance during one part of arevolution thereof and to retract during the remaining part of arevolution thereof.

5. In an imprinter; a frame, a rotary printing head and a pressuremember in radially opposed relation in said frame, means in said framefor advancing said printing head toward said pressure member intoprinting position and for retracting said printing head away from saidpressure member into idle position, ribbon supply means operable tosupply a ribbon into the space between said printing head and pressuremember which will imprint on a workpiece disposed between the ribbon andsaid pressure member when said printing head is advanced into printingposition, feed means for feeding said ribbon in the circumferentialdirection of said printing head when the printing head is advanced intoprinting position, said ribbon supply means includes means for rotatablysupporting a ribbon supply reel on said frame on one side of saidpressure member, said ribbon feed means being disposed in said frame onthe other side of said pressure member, a ribbon wound up on the supplyreel and leading therefrom to said feed means, first means for drivingsaid print head in rotation continuously, and second means for drivingsaid feed means only while said printing head is advanced into printingposition, and a bracket, a printing shaft journaled in said bracket andhaving said printing head mounted on one end thereof, pivot meanspivotally connecting the end of said bracket opposite the print head tosaid frame and said means for advancing and retracting said printinghead comprising a reversible actuator connected between said frame andan intermediate point of said bracket, said ribbon supply meansincluding a supply reel rotatable in said frame on one side of saidpressure member, said feed means including a take up reel rotatable inthe frame on the other side of said pressure member, ribbon guide meansbetween said reels and said pressure member guiding the ribbon in ahorizontal path which is spaced from said printing head when the latteris in retracted position, a pulley connected to said take up reel, apulley on said printing shaft, and a stretch belt entrained about saidpulleys which tightens up when said printing head is advanced toprinting position.

1. In an imprinter; a frame, a rotary printing head and a pressuremember in radially opposed relation in said frame, means in said framefor advancing said printing head toward said pressure member intoprinting position and for retracting said printing head away from saidpressure member into idle position, ribbon supply means operable tosupply a ribbon into the space between said printing head and pressuremember which will imprint on a workpiece disposed between the ribbon andsaid pressure member when said printing head is advanced into printingposition, feed means for feeding said ribbon in the circumferentialdirection of said printing head when the printing head is advanced intoprinting position, said ribbon supply means includes means for rotatablysupporting a ribbon supply reel on said frame on one side of saidpressure member, said ribbon feed means being disposed in said frame onthe other side of said pressure member, a ribbon wound up on the supplyreel and leading therefrom to said feed means, first means for drivingsaid print head in rotation continuously, and second means for drivingsaid feed means only while said printing head is advanced into printingposition, and a bracket, a printing shaft journaled in said bracket andhaving said printing head mounted on one end thereof, pivot meanspivotally connecting the end of said bracket opposite the print head tosaid frame and said means for advancing and retracting said printinghead comprising a reversible actuator conneCted between said frame andan intermediate point of said bracket, said feed means including a takeup reel rotatable in said frame and to which said ribbon is connected, apulley on said printing shaft, a pulley connected to said take up reel,and a stretch belt entrained about said pulleys, movement of saidprinting head into printing position drawing said belt tight to causedriving of said take up reel.
 1. In an imprinter; a frame, a rotaryprinting head and a pressure member in radially opposed relation in saidframe, means in said frame for advancing said printing head toward saidpressure member into printing position and for retracting said printinghead away from said pressure member into idle position, ribbon supplymeans operable to supply a ribbon into the space between said printinghead and pressure member which will imprint on a workpiece disposedbetween the ribbon and said pressure member when said printing head isadvanced into printing position, feed means for feeding said ribbon inthe circumferential direction of said printing head when the printinghead is advanced into printing position, said ribbon supply meansincludes means for rotatably supporting a ribbon supply reel on saidframe on one side of said pressure member, said ribbon feed means beingdisposed in said frame on the other side of said pressure member, aribbon wound up on the supply reel and leading therefrom to said feedmeans, first means for driving said print head in rotation continuously,and second means for driving said feed means only while said printinghead is advanced into printing position, and a bracket, a printing shaftjournaled in said bracket and having said printing head mounted on oneend thereof, pivot means pivotally connecting the end of said bracketopposite the print head to said frame and said means for advancing andretracting said printing head comprising a reversible actuator conneCtedbetween said frame and an intermediate point of said bracket, said feedmeans including a take up reel rotatable in said frame and to which saidribbon is connected, a pulley on said printing shaft, a pulley connectedto said take up reel, and a stretch belt entrained about said pulleys,movement of said printing head into printing position drawing said belttight to cause driving of said take up reel.
 2. An imprinter accordingto claim 1 in which said ribbon supply means comprises a supply reelrotatable in said frame and from which said ribbon leads, and a dragbrake connected to said supply reel.
 3. An imprinter according to claim1 in which said reversible actuator includes a double acting fluid motorhaving a reciprocable ram, and a yoke connected to said ram andpivotally connected between said frame and an intermediate point of saidbracket.
 4. An imprinter according to claim 3 which includes a reversingvalve connected to said fluid motor and actuating solenoids therefor,switch means connected in controlling relation to said solenoids, and acam rotating in unison with said printing head and operable to actuatesaid switch means to cause said printing head to advance during one partof a revolution thereof and to retract during the remaining part of arevolution thereof.